I was playing around with JavaScript/canvas and I want my objects color to depend on the distance to its center from current mouse position.This is my current function that gets color every mousemove event:
function getColorFromDistance(node1,node2){
var dist = getDist(node1,node2); //Getting distance;
var cl = (Math.round(255/dist*255)).toString(16); //this needs to be a propper formula
return "#" + cl + cl + cl; //converting to hex
}
Currently I get a blink effect when the distance gets 255.
I need a way to get the colors strength be depended on the distance, so that the further mouse is away from object the more its darken and when mouse is on the objects center its fully white.Well you get the idea.I just need the formula
The formula would be calculate the distance between the two points and get a percentage based on the maximum value (width of canvas/window)
//this would need to be recalulated on resize, but not doing it for demo
var targetElem = document.querySelector("div.x span");
box = targetElem.getBoundingClientRect(),
x = box.left + box.width/2,
y = box.top + box.height/2,
winBox = document.body.getBoundingClientRect(),
maxD = Math.sqrt(Math.pow(winBox.width/2, 2) + Math.pow(winBox.height/2, 2));
document.body.addEventListener("mousemove", function (evt) {
var diffX = Math.abs(evt.pageX-x),
diffY = Math.abs(evt.pageY-y),
distC = Math.sqrt(Math.pow(diffX, 2) + Math.pow(diffY, 2)),
strength = Math.ceil(255 - (distC/maxD*255)).toString(16),
color = "#" + strength + strength + strength;
targetElem.style.backgroundColor = color;
});
html, body { height: 100%; }
div.x { position: absolute; top: 50%; left:50%; }
span { display: inline-block; width: 20px; height: 20px; border-radius: 50%; border: 1px solid black; overflow: hidden; }
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<p>Test</p>
<div class="x"><span> </span></div>
I have a div1 which animates background position on hover direction of mouse by jquery.
But it's working properly. it's going not right direction and I want it to work on every single mouse hover on the div.
Find jsfiddle
code:
$(function() {
$(".mainCont").hover(function(e) {
// $(this).addClass("hoverOnce");
var edge = closestEdge(e.pageX, e.pageY, $(this).width(), $(this).height());
}, function(){
$(this).removeClass('top right bottom left');
// $(this).removeClass("hoverOnce");
});
});
function closestEdge(x,y,w,h) {
var topEdgeDist = distMetric(x,y,w/2,0);
var bottomEdgeDist = distMetric(x,y,w/2,h);
var leftEdgeDist = distMetric(x,y,0,h/2);
var rightEdgeDist = distMetric(x,y,w,h/2);
var min = Math.min(topEdgeDist,bottomEdgeDist,leftEdgeDist,rightEdgeDist);
switch (min) {
case leftEdgeDist:
$(".hoverOnce").addClass("left");
case rightEdgeDist:
$(".hoverOnce").addClass("right");
case topEdgeDist:
$(".hoverOnce").addClass("top");
case bottomEdgeDist:
$(".hoverOnce").addClass("bottom");
}
}
function distMetric(x,y,x2,y2) {
var xDiff = x - x2;
var yDiff = y - y2;
return (xDiff * xDiff) + (yDiff * yDiff);
}
The size of this image that you use in the background is 700x500:
http://thesis2010.micadesign.org/kropp/images/research/bird_icon.png
I think that if you add these settings to .mainCont that this will get you the desired result:
width: 700px;
height: 500px;
position: absolute;
For example:
.mainCont {
width: 700px;
height: 500px;
background: url(http://thesis2010.micadesign.org/kropp/images/research/bird_icon.png) no-repeat center center;
transition: all 0.5s ease-in-out;
margin: 100px auto;
position: absolute;
}
Fiddle
Finally, It got solved.
find fiddle demo
$('.mainCont').hover(function(e){
var dir = determineDirection($(this), {x: e.pageX, y: e.pageY});
$(this).addClass('direction_'+dir);
}, function() {
$(this).removeClass('direction_3 direction_1 direction_2 direction_0');
});
function determineDirection($el, pos){
var w = $el.width(),
h = $el.height(),
x = (pos.x - $el.offset().left - (w/2)) * (w > h ? (h/w) : 1),
y = (pos.y - $el.offset().top - (h/2)) * (h > w ? (w/h) : 1);
return Math.round((((Math.atan2(y,x) * (180/Math.PI)) + 180)) / 90 + 3) % 4;
}
I have been trying to modify a code which scrolls the images horizontally. I want to scroll it vertically. I don't know JQuery at all. After trying for hours I couldn't find any way to sort this thing out. Can anyone help me out in this regard.
Heres the whole code.
$(function() {
$(window).load(function() {
var $gal = $("#propertyThumbnails"),
galW = $gal.outerWidth(true),
galSW = $gal[0].scrollWidth,
wDiff = (galSW / galW) - 1, // widths difference ratio
mPadd = 60, // Mousemove Padding
damp = 20, // Mousemove response softness
mX = 0, // Real mouse position
mX2 = 0, // Modified mouse position
posX = 0,
mmAA = galW - (mPadd * 2), // The mousemove available area
mmAAr = (galW / mmAA); // get available mousemove fidderence ratio
$gal.mousemove(function(e) {
mX = e.pageX - $(this).parent().offset().left - this.offsetLeft;
mX2 = Math.min(Math.max(0, mX - mPadd), mmAA) * mmAAr;
});
setInterval(function() {
posX += (mX2 - posX) / damp; // zeno's paradox equation "catching delay"
$gal.scrollLeft(posX * wDiff);
}, 10);
});
});
#parent {
position: relative;
margin: 0 auto;
width: 100%;
background: #ddd;
}
#propertyThumbnails {
position: relative;
overflow: hidden;
background: #444;
width: 100%;
white-space: nowrap;
}
#propertyThumbnails img {
vertical-align: middle;
display: inline;
margin-left: -4px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div id="parent">
<div id="propertyThumbnails">
<img src="http://placehold.it/1000x100" />
</div>
</div>
Heres the demo:
http://jsbin.com/alokat/1/edit?html,css,js,output
I changed the script as
$(function(){
$(window).load(function(){
var $gal = $("#propertyThumbnails"),
galW = $gal.outerHeight(true),
galSW = $gal[0].scrollHeight,
wDiff = (galSW/galW)-1, // widths difference ratio
mPadd = 60, // Mousemove Padding
damp = 20, // Mousemove response softness
mX = 0, // Real mouse position
mX2 = 0, // Modified mouse position
posX = 0,
mmAA = galW-(mPadd*2), // The mousemove available area
mmAAr = (galW/mmAA); // get available mousemove fidderence ratio
$gal.mousemove(function(e) {
mX = e.pageY - $(this).parent().offset().top - this.offsetTop;
mX2 = Math.min( Math.max(0, mX-mPadd), mmAA ) * mmAAr;
});
setInterval(function(){
posX += (mX2 - posX) / damp; // zeno's paradox equation "catching delay"
$gal.scrollTop(posX*wDiff);
}, 10);
});
});
I am having trouble trying to implement a "prize wheel," using canvas. I am using something similar to the canvas "roulette wheel" http://jsfiddle.net/wYhvB/4/ that is floating around StackOverflow. My dilema is when you click spin, in the background I make an API call that returns an id of which prize should actually be chosen, the interface is nothing more than eye candy. I am pushing all the prize descriptions into the first array, how can I add an id into each one of the arcs and stop on a particular one instead of stopping on a specifically random time? I.E. If the API returns "car," I want this wheel to spin a few times and stop on car.
var colors = ["##eaeaea", "##cccccc", "##eaeaea", "##cccccc",
"##eaeaea", "##cccccc", "##eaeaea", "##cccccc"];
// NEED to pre load this data prior
var prize_descriptions = ["car","house","etc..."]; // These are injected on an init call from an api
var current_user_status = {};
var startAngle = 0;
var arc = Math.PI / 4;
var spinTimeout = null;
var spinArcStart = 10;
var spinTime = 0;
var spinTimeTotal = 0;
var current_user_status = null;
var spin_results = null;
var ctx;
function drawSpinnerWheel() {
var canvas = document.getElementById("canvas");
if (canvas.getContext) {
var outsideRadius = 200;
var textRadius = 160;
var insideRadius = 125;
ctx = canvas.getContext("2d");
ctx.clearRect(0,0,500,500);
ctx.strokeStyle = "black";
ctx.lineWidth = 2;
ctx.font = 'bold 12px Helvetica, Arial';
for(var i = 0; i < 8; i++) {
var angle = startAngle + i * arc;
ctx.fillStyle = colors[i];
ctx.beginPath();
ctx.arc(250, 250, outsideRadius, angle, angle + arc, false);
ctx.arc(250, 250, insideRadius, angle + arc, angle, true);
ctx.stroke();
ctx.fill();
ctx.save();
ctx.shadowOffsetX = -1;
ctx.shadowOffsetY = -1;
ctx.shadowBlur = 0;
ctx.shadowColor = "rgb(220,220,220)";
ctx.fillStyle = "black";
ctx.translate(250 + Math.cos(angle + arc / 2) * textRadius,
250 + Math.sin(angle + arc / 2) * textRadius);
ctx.rotate(angle + arc / 2 + Math.PI / 2);
var text = prize_descriptions[i];
if (text == undefined)
text = "Not this time! "+i;
ctx.fillText(text, -ctx.measureText(text).width / 2, 0);
ctx.restore();
}
//Arrow
ctx.fillStyle = "black";
ctx.beginPath();
ctx.moveTo(250 - 4, 250 - (outsideRadius + 5));
ctx.lineTo(250 + 4, 250 - (outsideRadius + 5));
ctx.lineTo(250 + 4, 250 - (outsideRadius - 5));
ctx.lineTo(250 + 9, 250 - (outsideRadius - 5));
ctx.lineTo(250 + 0, 250 - (outsideRadius - 13));
ctx.lineTo(250 - 9, 250 - (outsideRadius - 5));
ctx.lineTo(250 - 4, 250 - (outsideRadius - 5));
ctx.lineTo(250 - 4, 250 - (outsideRadius + 5));
ctx.fill();
}
}
function spin() {
spinAngleStart = Math.random() * 10 + 10;
spinTime = 0;
spinTimeTotal = Math.random() * 3 + 4 * 1000;
rotateWheel();
}
function rotateWheel() {
spinTime += 30;
if(spinTime >= spinTimeTotal) {
stopRotateWheel();
return;
}
var spinAngle = spinAngleStart - easeOut(spinTime, 0, spinAngleStart, spinTimeTotal);
startAngle += (spinAngle * Math.PI / 180);
drawSpinnerWheel();
spinTimeout = setTimeout('rotateWheel()', 30);
}
function stopRotateWheel() {
clearTimeout(spinTimeout);
var degrees = startAngle * 180 / Math.PI + 90;
var arcd = arc * 180 / Math.PI;
var index = Math.floor((360 - degrees % 360) / arcd);
ctx.save();
ctx.font = 'bold 30px Helvetica, Arial';
var text = prize_descriptions[index];
ctx.fillText(text, 250 - ctx.measureText(text).width / 2, 250 + 10);
ctx.restore();
}
function easeOut(t, b, c, d) {
var ts = (t/=d)*t;
var tc = ts*t;
return b+c*(tc + -3*ts + 3*t);
}
drawSpinnerWheel();
$("#spin").bind('click', function(e) {
e.preventDefault();
spin();
});
I have some experience in creating HTML5 canvas winning wheels, the way that I solved the problem of getting the wheel to stop at at a particular prize determined by a server-side process was to define an array of prizes that correspond to what is shown on the wheel, specifying the start and end angle of each prize in degrees, and then before the wheel is rotated setting a targetAngle to a random value between the start and end angle of the prize in question plus adding a multiple of 360 degrees so that the wheel spins a few times before slowing to a stop at the predetermined prize.
For example if the wheel has 4 prizes then the prizes array is...
var prizes = new Array();
prizes[0] = {"name" : "Prize 1", "startAngle" : 0, "endAngle" : 89};
prizes[1] = {"name" : "Prize 2", "startAngle" : 90, "endAngle" : 179};
prizes[2] = {"name" : "Prize 3", "startAngle" : 180, "endAngle" : 269};
prizes[3] = {"name" : "Prize 4", "startAngle" : 270, "endAngle" : 359};
And the code to set the targetAngle is something like...
targetAngle = Math.floor(prizes[determinedPrize]['startAngle'] + (Math.random() * (prizes[determinedPrize]['endAngle'] - prizes[determinedPrize]['startAngle'])));
targetAngle += (360 * 18);
The spinning function of the wheel then loops until the current angle of the wheel equals the targetAngle.
A working example of my prize wheel and the fully commented source code is available at http://www.dougtesting.net. The pre-determined feature is not enabled in the online example, but can easily be turned on in the source code (winwheel.js) once downloaded.
The easiest way I can think of is to take the current position of the wheel, then calculate the distance from this point to the prize. Add a random number of multiples of the wheel diameter circumference and then you have a distance. The edge of the wheel must travel through this distance to end up at the prize.
Just like you can use linear or cubic interpolation to move an element from 1 position to another in a specified number of steps, you can use the same approach to rotate the wheel from point 0 (start point) to point 1 (end point) from time=0 to time=1
This page Math: Ease In, ease Out a displacement using Hermite curve with time constraint is a good read. It's where I managed to wrap my head around doing basically the same thing - just up/down/left/right, rather than rotationally.
It's a bit choppy while im look at iot just now. Dont know if it's jsfiddle, the missing images or the 25 browser tabs & programs I have running.
Anyway, the point is to use non-linear interpolation to get to a specified distance away in a specified number of steps. It should get there in a specified time, but not with 25 windows open.. :laughs:
Check out the SO link above. It's got some great pictures that really explain quite well.
Here's a fiddle of cubic-spline interpolation for the time.
http://jsfiddle.net/enhzflep/XKzGF/
And here's the full code:
<!DOCTYPE html>
<html>
<head>
<script>
var continuePlaying = true, isPlaying=false;
function byId(a){return document.getElementById(a)}
function myInit()
{
}
window.addEventListener("load",myInit,!1);
function cubicHermite(a,b,d,e,c){var g=a*a,f=g*a;return(2*f-3*g+1)*b+(f-2*g+a)*e+(-2*f+3*g)*d+(f-g)*c}
function interp(a,b,d,e,c){var g,f;f=e/(a/2+b+d/2);g=f*a/2;f*=b;return result=c<=a?cubicHermite(c/a,0,g,0,f/b*a):c<=a+b?g+f*(c-a)/b:cubicHermite((c-a-b)/d,g+f,e,f/b*d,0)}
function linear(a){return a}
function cubic(a){return interp(0.35,0.3,0.35,1,a)}
function getSize(a){return{left:a.offsetLeft,top:a.offsetTop,width:a.clientWidth,height:a.clientHeight}}
function doAnim2(a,b,d,e){var c=a/b;setTimeout(function(){doAnimStep(0,b,c,d,e)},c)}
function doAnimStep(a,b,d,e,c){a<=b?(setTimeout(function(){doAnimStep(a,b,d,e,c)},d),e(a/b),a++):void 0!=c&&null!=c&&c()}
//scroll with cubic interpolation of the current scroll position
function cubicScrollDown(b,callback)
{
var a=byId(b),c=a.scrollHeight-a.clientHeight;
doAnim2(500,c,function(b){a.scrollTop=c*cubic(b)},callback);
}
function cubicScrollUp(b,callback)
{
var a=byId(b),c=a.scrollHeight-a.clientHeight;
doAnim2(500,c,function(b){ a.scrollTop=c*(1-cubic(b)) },callback );
}
//scroll with cubic interpolation of the current scroll position
function linearScrollDown(b, callback)
{
var a=byId(b),c=a.scrollHeight-a.clientHeight;
doAnim2(500,c,function(b){a.scrollTop=c*linear(b)}, callback);
}
function linearScrollUp(b, callback)
{
var a=byId(b),c=a.scrollHeight-a.clientHeight;
doAnim2(1000,c,function(b){ a.scrollTop=c*(1-linear(b)) }, callback );
}
function animFadeOut(elem, callback)
{
doAnim2(500,50,function(raw){elem.style.opacity=1-cubic(raw)},callback);
}
function animFadeIn(elem, callback)
{
doAnim2(500,50,function(raw){elem.style.opacity=cubic(raw)},callback);
}
function cubicBounce(b)
{
cubicScrollDown(b, downCallback);
function downCallback()
{
cubicScrollUp(b, upCallback);
}
function upCallback()
{
if (continuePlaying===true)
setTimeout( function(){cubicBounce(b);}, 0);
else
continuePlaying = true;
}
}
function linearBounce(b)
{
linearScrollDown(b, downCallback);
function downCallback()
{
linearScrollUp(b, upCallback);
}
function upCallback()
{
if (continuePlaying===true)
setTimeout( function(){linearBounce(b);}, 0);
else
continuePlaying = true;
}
}
function fadeOutIn(tgtListIdStr)
{
var tgt = byId(tgtListIdStr);
animFadeOut(tgt,fadedOutCallback);
function fadedOutCallback()
{
animFadeIn(tgt);
}
}
function prependChild(parent, element)
{
if (parent.childNodes)
parent.insertBefore(element, parent.childNodes[0]);
else
parent.appendChild(element)
}
function slideUpRemove(tgtListIdStr)
{
var tgt = byId(tgtListIdStr);
var listItems = tgt.getElementsByTagName('li');
mHeight = listItems[0].clientHeight;
animFadeOut(listItems[0], slideUp);
function slideUp()
{
doAnim2(500, 50, slideUpStep, slideUpDone);
function slideUpStep(raw)
{
listItems[0].style.height = (cubic(1-raw) * mHeight) + 'px';
}
function slideUpDone()
{
dummy = listItems[0];
tgt.appendChild(dummy);
//dummy.removeAttribute('style');
dummy.style.height = null;
dummy.style.opacity = null;
}
}
}
function slideDownInsert(tgtListIdStr)
{
// get the container, it's items and the height of the last LI item.
var tgt = byId(tgtListIdStr);
var listItems = tgt.getElementsByTagName('li');
mHeight = listItems[listItems.length-1].clientHeight;
// create a dummy to take the place of the last item, set it's size and height. make it the first child of the containing list
var dummy = document.createElement('li');
dummy.style.opacity = 0;
dummy.style.height = 0 + 'px';
prependChild(tgt, dummy);
// animate it!
doAnim2(500, 50, slideDownStep,slideDownDone);
function slideDownStep(raw)
{
dummy.style.height = (cubic(raw) * mHeight)+'px';
}
function slideDownDone()
{
// remove the dummy
var newItem = listItems[listItems.length-1];
newItem.style.opacity = 0;
prependChild(tgt, newItem);
tgt.removeChild(dummy);
animFadeIn(newItem, function(){newItem.removeAttribute('style')});
}
}
</script>
<style>
#myListDiv
{
width: 256px;
padding: 6px;
height: 128px;
overflow-y: hidden; /*scroll;*/
border-radius: 6px;
border: solid 1px transparent;
border-color: rgba(0,0,0,0.2) rgba(255,255,255,0.4) rgba(255,255,255,0.4) rgba(0,0,0,0.2);
/* background-image: url(img/rss128.png); */
background-color: rgba(0,0,0,0.1);
}
h4, p
{
margin: 6px 0;
}
ul
{
padding: 0;
list-style: none;
margin: 0;
}
ul#mList li
{
padding: 0 8px;
margin: 0 6px;
display: block;
border: solid 1px #cccccc;
border-bottom-color: #000;
border-color: #ccc transparent #000 transparent;
vertical-align: middle;
background-color: rgba(150,150,150,0.95);
overflow: hidden;
}
.thumb
{
width: 48px;
height: 48px;
float: left;
}
.thumb img
{
height: 48px;
}
#mPanel
{
display: inline-block;
float: left;
padding: 32px;
background-color: hsl(80,50%,20%);
}
</style>
</head>
<body>
<div id='mPanel'>
<div id='myListDiv'>
<ul id='mList'>
<li><div class='thumb'><img src='img/opera.svg'></div><div class='itemData'><h4><a>Item #1</a></h4><p>some assorted text</p></div></li>
<li><div class='thumb'><img src='img/chromeEyes.svg'></div><h4><a>Item #2</a></h4><p>some assorted text</p></li>
<li><div class='thumb'><img src='img/girl.png'></div><h4><a>Item #3</a></h4><p>some assorted text</p></li>
<li><div class='thumb'><img src='img/chuck-norris.jpg'></div><h4><a>Item #1</a></h4><p>some assorted text</p></li>
<li><div class='thumb'><img src='img/redBaron.jpg'></div><h4><a>Item #2</a></h4><p>some assorted text</p></li>
<li><div class='thumb'><img src='img/default.png'></div><h4><a>Item #3</a></h4><p>some assorted text</p></li>
</ul>
</div>
</div>
<button onclick='cubicScrollDown("myListDiv")'>Cubic down</button>
<button onclick='cubicScrollUp("myListDiv")'>Cubic up</button><br>
<button onclick='cubicBounce("myListDiv")'>cubic bounce</button>
<button onclick='linearBounce("myListDiv")'>linear bounce</button><br>
<input type='button' onclick='slideUpRemove("mList")' value='newest'/>
<input type='button' onclick='slideDownInsert("mList")' value='Slide Down'/><br>
<button onclick='continuePlaying=false'>Stop Anim cycle</button>
<input type='button' onclick='fadeOutIn("mList");' value='fadeOutIn'/><br>
</body>
</html>